Subject: 3.5-m Users Committee minutes 6/09/08

From: Bruce Gillespie

Submitted: Thu, 12 Jun 2008 14:34:46 -0600

Message number: 1106 (previous: 1105, next: 1107 up: Index)

           APO 3.5-m Users Committee Phonecon, 6/09/08

Attending:  Suzanne Hawley, Bruce Gillespie, Scott Anderson, John  
Bally, Jon Holtzman, Michael Strauss, Bill Ketzeback, and Remy  

Absent: Al Harper, Jon Fulbright, Mark Klaene

Minutes taken by Bruce Gillespie


User feedback, comments from institutional representatives:

None of the committee members present had any substantive user issues  
to report.


Discussion of telescope/instruments report - Gillespie:

The report is given below.  Bruce highlighted the site issues (unusual  
weather, water-leak fix, etc.).  John Bally updated the NIC-FPS status  
by saying that the etalon is now at CU being prepared for cryo  
testing.  Also, based on discussions with UVa instrument engineers, a  
second new fan-out board will be fabricated this summer in the hope of  
further reducing detector read noise.  Bill Ketzeback talked about the  
ongoing development and testing of the telescope autofocus capability,  
which the Observing Specialists are using in beta test mode.  These on- 
sky tests are yielding encouraging results, and more tuning and  
refinements are in the works.  Suzanne mentioned that the Q3 schedule  
was posted yesterday, and she invites the users to check their  
programs.  Because of the summer shutdowns and high demand for  
TripleSpec, the bright time in Q3 was especially oversubscribed, more  
so than usual.


3.5-m Telescope, Instruments, and CIF Projects Highlights, 4/30/08  
through 6/05/08

                    Mark Klaene & Bruce Gillespie

0) Overview

Operations continued to be largely routine through the period. Unusual  
spring weather has caused several nights of lost observing due to  
several episodes of high winds and elevated dust levels. The  
surrounding forest remained closed by the USFS (since May 1st) due to  
extreme fire danger, although this has not affected operations. Minor  
amounts of rain and elevated humidity have somewhat reduced the fire  
danger, and the wind and dust are starting to subside as we approach  
the summer monsoons. However, we are also coming into the seasonal  
pine-tree mating season, and telescope closure guidelines will be  
strictly enforced because pollen is somewhat caustic to mirrors and  
difficult to remove with CO2 snow cleaning procedures.

On site-related matters, we noticed that recent water consumption at  
the site was still above normal despite earlier repair work, and  
another underground water leak was subsequently located and fixed.  
Site electric power was also relatively unstable, due to the high  
winds that have caused fluctuations and outages in the county-wide  
grid. We are also planning to repair the fuel leak in the diesel  
backup generator later this month, although the generator is still  
operational in the meantime.

1) Telescope

Tertiary rotation acted up again even after replacing its encoder. The  
engineering staff is working on diagnosing the problem, however a  
detailed inspection of the system will not occur until the summer  
shutdown when we have the entire system apart. A telescope autofocus  
script is being tested and refined; initial on-sky results look  

2) Instruments

DIS, SPIcam, and the Echelle operated smoothly throughout the period.  
The new fan-out board replacement for NIC-FPS and the etalon removal  
work was completed. The dysfunctional etalon is now at CU for  
evaluation. The new fan-out board did not eliminate all of the excess  
detector read noise, only about a 40% reduction in noise was seen. A  
CU team returned to the site to work on the noise problem some more.  
It is now believed that additional modifications to the fan-out board  
will be required, involving adding capacitors.

TripleSpec commissioning continues. Preliminary user documentation is  
now available at the APO home page. The visiting instruments, GFP and  
APOLLO, were both operational.

3) CIF projects

We made progress on the implementation of Agile field rotation and  
migration to the TR2 mirror cell port. During initial bench testing  
one of the Hall effect sensors was discovered to be defective. The  
motor was subsequently sent back to the vendor for warranty repair.  
The machined parts for moving Fastcam to its new port are complete and  
ready for installation, which will free up the TR2 port for Agile.

The tertiary support/actuator upgrade is progressing. Design work is  
still slightly behind schedule but remains on track for an August  
installation. Ongoing cleanup of rotator axis controller software  

4) Summer Shutdowns (Unchanged from last month)

There will be three shutdown periods this summer. Two 3-day shutdowns,  
one in June and one in July, will be for secondary and axis drive  
work. In August, we are planning a 17-day shutdown for the tertiary  
support/actuator upgrade, as well as for M1 washing and several  
additional maintenance tasks (e.g., annual instrument servicing).


Narrow-band filters for Agile - Hawley:

Suzanne raised the issue of possible user interest in using narrow- 
band filters with Agile.  Normally, people will be using our stock 3 x  
3 inch broad-band SDSS or Johnson filters with Agile, but there may be  
Agile science applications that favor narrow-band filters (e.g.,  
planetary occultations).  Because of the optical layout of the  
instrument, the stock 2 x 2 inch narrow-band filters at APO will cause  
significant vignetting in Agile's focal plane, which will severely  
limit the field of view.  Suzanne suggested that if there are users  
planning to use Agile with narrow-band filters, they should contact us  
so that we can determine if we need to procure the larger narrow-band  

ACTION:  Users committee members and users should contact Suzanne and  
Mark Klaene (slh at, mark at if  
they intend to use narrow-band filters for their future Agile science  


TripleSpec observing during Q3 - Hawley:

Suzanne reminded us that TripleSpec will be used in campaign mode  
during Q3 on a shared-risk basis, and that the UVa instrument  
developers will be on-call during the campaigns to help with  
unexpected problems.  TripleSpec user documentation and test data is  
available through our website, as well as pipeline data reduction  


SDSS-III update - Gillespie, Hawley:

Bruce reported on the recent NSF review of the SDSS-III proposal.   
Although we will not likely hear the official results of the review  
for a few weeks, apparently the review was "successful" from the NSF's  
perspective.  Once the NSF makes its funding decision, the funding  
partners (NSF, Sloan, DoE, and MOU institutions) will likely try to  
have a conference to assemble a joint funding plan for the survey.



[open from previous months]:


[new actions from this month]:

ACTION:  Users committee members and users should contact Suzanne and  
Mark Klaene (slh at, mark at if  
they intend to use narrow-band filters for their future Agile science  


New business - Hawley:

Although not on the agenda, Suzanne mentioned that she wanted the  
committee to be aware that we have received a proposal for a new  
visiting instrument.  John Bally and Jian Ge are jointly planning to  
build a very-high-resolution NIR spectrograph that uses a silicon  
immersion grating.  It is conceivable that the prototype instrument  
could be placed at the 3.5-m telescope as early as this winter.  As  
well as being a complementary instrument for extra-solar planet RV  
studies, it could support follow-up observations of APOGEE survey  
targets.  A white paper is being prepared for further discussion.


Next meeting:

The next Users Committee phonecon will be on Monday, 4 Aug, at 8:30 AM  
Pacific Time (we will skip the meeting in July).  The agenda and other  
materials will be sent to the committee members during the preceding  

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